Tin sinter and method of producing same



Patented Mar. 18, 1924.

uurrs o m an r NT *QFFEQ HARRY H. A EXANDER," or WESTFIELD, NEW JERSEY, Assienon 'ro AMERICAN SMELTING' AND annu us COMPANY, OF NEW YORK, n. Y., A CORPORATION ,on

NEW JERSEY.

TTN SI'NTER AND METHOD OF PRODUCING SAME.

No Drawing.

metallurgical process of forming tin sinter and. specifically constitutes a preliminary step in the recovery of metallic tin from ores and other tin bearing material.

The invention also relates to a prepared sinter for use in charging a blast furnace or similar furnaces for the recovery of metallic tin by a smelting operation.

One form of tin bearing material with which the present disclosure can be operated I efficiently is tin concentrates which contains,

in addition to tinof 50% to 70% by weight, certain other elements herein identifiedcollectively as foreign elements and which in-' clude sulphur, arsenic, antimony and the other elements and compounds usually The invention contemplates the sintering of these ores before charging them into the blast furnace and the present disclosure particularly relates to the preliminary treatment of the tin bearing;

material'in order to place thesame in condition suitable for the blast furnace.

Accordingly one of the objects of the in:

. vention is to provide a simple means which may be practiced economically on a large commercial scale for efiiciently preparing tin sinter. I

The tin bearing material is ground, if necessary, and the ground material is then roasted where it is required to remove sulphur and certain of the more volatile foreign elements. It is preferable that the roastin be continued until the sulphur is eliminate or at least until there is less than one-half of one per cent sulphur present in the roastedmaterial. t

This removal of the sulphur is necessary as the presence of any material amount of this element would cause the same to combine with some of the tin in the blast furnace to form matte with a resulting loss in tin.

The roasted material is mixed with a suitable binder such as granulated tin slag, silica, or silicio'us flux or other tin ore agwith flu-xes' and other reagents Application filed October 25, 1920. serial No. 419,473. J

glomerating material; There is also added to the mixture certain fluxing substances to combine with the sulphur remaining in the ore and it is suggested that limestone is one such fluxing agent. This'limestone further acts to prevent the formation of tin matte in the succeeding steps of theoperation by combining with the sulphur to form calcium sulphate. 'Carbonaceous material such as fine coal is added as fuel in the sintering step and this carbonaceous material per forms the additional and incidental function of a reducing agent Water is added to moisten the mixture and the moistened mixture is sintered as is usual with such processes. This step can be performed satisfactorily ona Dwight & Lloyd sintering ma-- chine. The chargeon the sintering machine is ignited by any of the usual methods as by the use of an oil burner and when completely sintered is ready to be combined and fed to the blastfurnace.

The produced productv consists-of a porv ous, lump material containing certain natural constituents of the ore together with the tin mainly in the form' of stannous oxide-and calcium-compounds. The, constituents are bound together by the granulated slag and .silieious flux and can be broken up and charged into'the blast furnace without further treatment.

Having thus described my invention, ,1. Y

claim:

1. In the artof producing tin sinter from tin concentrates and like tin containing material which may also contain certain foreign elements such as sulphur, arsenic and antimony, the process which consists in finely dividing the material, roasting the;

sameto partially remove some of the foreign elements, combining the roasted material with a binder and carbonaceous matter together wlth a reagenteapable of combining with the remaining sul hur, moistening the mixture and sintering the moist mixture.

2. In the art'of producing tinv sinter from tin concentrates and like tin containing material which may also contain certain foreign elements such as sulphur, arsenic and anti mony, the process which consists, in finely dividing the material, roasting the same to partially remove some of the foreign elepable of combining with the remaining sulphur, moistening the mixture and sintering the moist mixture.

3. In the art of producing tin sinter from tin concentrates and like tin containing material which may also contain certain foreign elements such as sulphur, arsenic and antimony, the process which consists in finely dividing the material, roastingthel same to partially remove some of the foreign elements, combinin the roasted material with a binder toget er with limestone and carbonaceous matter, moistening the mixture and sintering the moist mixture.

4. In the art of producing tin sinter from tin concentrates and like tin containing'material which may also contain sulphur, the process which consists in roasting the material to partially remove the sulphur, if present, con'ibining the roasted product with an agglon'ieratingmaterial, a fuel, a siilphur reducing reagent and water, and sintering the wet mixture.

5. In the art of producing tin sinter from tin concentrates and like tin containing ma terial, the process which consists in roasting the mate-rial, combining the roasted product with an agglomerating material, a reducing fuel and water, and sintering the wet mixture.

6. In the art of producing tin sinter from tin concentrates and other tin containing materials which may contain foreign .elements in addition to tin, the process which consists in grinding the material, roasting the ground material, mixing the roasted material with granulated tin slag, silicious material, limestone and carbonaceous fuel, moistening the mixture and sintering the moistened mixture.

7. In the art of producing tin sinter from tin concentrates and other tin containing materials which may contain foreign elements in addition to tin, the process which consists in roasting the material to remove some of the foreign elements present, mixii the roasted materialwith a binder, suppying fuel, if necessary, to maintain a sintering action, moistening the mixture and sintering the moist mixture.

8. In the art of producing tin sinter from tin concentrates and other tin containing matin concentrates and other tin containing materials which may contain foreign elements in addition to tin,'the process which consists in grinding the material'to a finely divided condition, roasting the ground materialto remove some of the foreign elements, combining the roasted material, supplying fuel, if necessary, to maintain a sintermg action with a reagent capable of preventing the formation of tin matte in the succeeding sintering step and sintering the mixture.

10. In the art of producing tin sinter from tin containing material containing sulphur,

the process which consists in roasting the material, combining the roasted material with reagents capable of preventing the formation of tin-matte and of combining with the sulphur remaining in the roasted material, and sintering the mixture.

11. In the art of treating tin bearing ores to produce a sinter for smelting in a blast furnace, the process which consists in partially removing the sulphur if present, mixing the ore with a reducing material and with a fluxing material adapted to combine with any sulphura-nd prevent the formation of a matte, and then subjecting the mixture to a sintering operation.

12. A composition of matter constituting a tin sinter for use in feeding a blast furnace to recover tin, comprising a porous, lumpy material including sta'nnous oxlde and calcium com-pounds bound together by granulated slag and capable of being broken up.

13. A composition of matter constituting a tin sinterfor us'ein feeding a blast furnace to recover tin, comprising a porous, lumpy material including a reduced oxide of tin substantially free of sulphur.

Signed at New York city, in the county of New York and State of New York, this 13th day of @ctober, A. D. 1920.

HARRY II. ALEXANDER. 

